Hydroconversion of asphaltenes with a coke promoter

ABSTRACT

An asphaltene hydroconversion process for the conversion of asphaltenes to lower boiling hydrocarbons by contacting said asphaltenes with hydrogen in the presence of a selectively oxidized coke, an ammonia-treated coke and mixtures thereof.

United States Patent lnventors Edward L. Cole Flshklll; Edwin C. Knowles, Poughkeepsie, both of N.Y. Appl. No. 822,317 Filed May 6, 1969 Patented Nov. 2, 1971 Assignee Texaco Inc.

New York, N.Y.

HYDROCONVERSION 0F ASPHALTENES WITH A COKE PROMOTER 10 Claims, No Drawings U.S. CI 208/108, 208/143, 252/444, 252/445 Int. Cl. C 103 13/02, C 10g 13/04 Field 01 Search 208/ 108,

[56] References Cited UNITED STATES PATENTS 1,819,166 8/1931 l-lass 252/445 2,707,673 5/1955 Sweitzer et al. 252/445 3,211,673 10/1965 Luntz et a1 252/445 2,120,295 6/1938 Pier et al 208/108 2,325,072 7/1943 Pier et al.... 208/108 2,761,822 9/1956 Addison 252/445 2,950,242 8/1960 Thorpe et al. 208/108 3,356,756 12/1967 Schultz et a]. 252/445 Primary Examiner- Herbert Levine Attorneys- K. E. Kavanagh and Thomas H. Whaley ABSTRACT: An asphaltene hydroconversion process for the conversion of asphaltenes to lower boiling hydrocarbons by contacting said asphaltenes with hydrogen in the presence of a selectively oxidized coke, an ammonia-treated coke and mixtures thereof.

HYDROCONVERSION F ASPHALTENES WITH A COKE PROMOTER This invention relates to a hydroconversion process for increasing the yield of lower boiling hydrocarbons and more particularly to a hydrocracking process wherein an asphaltene containing heavy hydrocarbon charge stock is contacted with hydrogen in the presence of selectively oxidized coke and/or ammonia treated coke.

Generally, hydrocracking finds its highest degree of utility in the cracking of hydrocarbons boiling in the heavy naphtha and light gas oil range. It has however met with only limited acceptance in the upgrading of heavy hydrocarbon oils, particularly those containing high boiling asphaltenes and substantial sulfur and nitrogen contents such as total crude oil, topped crudes and residua, shale oil, coal tars, etc. The various sulfur and nitrogen compounds present in such oils tend to poison the hydrocracking catalyst and to deposit coke during catalytic hydrocracking operation, whereas the conversion of asphaltenes is accompanied by the deposition of carbon and metals. It has been particularly found that the higher boiling petroleum fractions of such oils, i.e. those fraction boiling above about 750 F., and particularly above about 850 F., contain relatively high proportions of the above-mentioned asphaltenes and objectionable contaminating materials. Accordingly, conventional hydrocracking of such fractions, or of oil feeds containing such fractions, has proved to be of very limited effectiveness.

It will be appreciated, therefore, that there is presently a high incentive for discovering a successful means for hydrocracking heavy hydrocarbon stocks containing asphaltenes to valuable lower boiling products.

It is therefore an object of this invention to provide an improved process for hydrocracking such feeds whereby higher yields of lower boiling hydrocarbons are obtained without substantial deposition of carbon.

It has now been found that lower boiling hydrocarbons can be obtained from an asphaltene containing heavy hydrocarbon charge stocks by a process which comprises contacting said heavy hydrocarbon charge stock with hydrogen in the presence of a promoting amount of a modified coke promoter selected from the group consisting of oxidized coke, ammonia treated coke and mixtures thereof for a time sufficient under hydrogen contact conditions of pressure and temperature to convert at least a portion of the asphaltenes to lower boiling hydrocarbons and recovering lower boiling hydrocarbons provided that said oxidized coke is prepared by the oxidation of coke in a yield of at least about 75 percent by weight based upon the original weight of coke. Thus it has been discovered that the hydrogen contact step in the presence of such modified coke promoter produces conversion of asphaltenes to lower boiling hydrocarbons without substantial formation of carbon. In addition the modified coke promoter can be continuously used and in addition recovered from the process of this invention and regenerated for further use.

In general the process of this invention is carried out by contacting the asphaltene containing heavy hydrocarbon charge stock with hydrogen in the presence of a promoting amount of the modified coke promoter. The term mixtures thereof refers to both mixtures of different oxidized coke, mixtures of different ammonia treated cokes as well as mixtures of one or more oxidized cokes with one or more ammonia treated cokes. The term "promoting amount" is used herein to be that concentration by weight of promoter which during the hydrogen contact step produces a yield of lower boiling hydrocarbons from asphaltenes greater than the yield of lower boiling hydrocarbons from asphaltenes obtained in the absence of the modified coke promoter. In general a concentration of modified coke promoter of from about 0.5 percent to about 20 percent, more preferably from about 2.0 percent to about l5 percent based upon the weight of the heavy hydrocarbon charge stock is utilized during the hydrogen contact step. The lower boiling hydrocarbon fractions are then recovered from the charge stock by conventional means, such as by distillation or vacuum stripping optionally using an inert stripping gas.

The conditions for hydrogen contact can be varied over a wide range as to liquid hourly space velocity (LHSV, volume of feed to volume of contactor per hour), volume of hydrogen to volume of heavy hydrocarbon charge stock (s.c.f. standard cubic feet/bbl.), temperature, pressure and the concentration of modified coke promoter. These conditions are adjusted in order to produce a hydrogen contact. step wherein the hydrogen and modified coke promoter are present in a concentration sufficient to effect production of lower boiling hydrocarbons and are adjusted in order to maximize the yield of lower boiling hydrocarbons from the heavy hydrocarbon charge stock while minimizing any carbon formation.

it is contemplated within the scope of this invention that the process when practiced on a continuous basic can provide for recycle of nonconverted asphaltenes to the charge stock for reprocessing. By the use of the term without substantial formation of carbon is meant that the process of this invention provides for less than 0.35 percent by weight carbon formation based upon the total weight of asphaltenes present in the charge stock still more preferably less than 0.06 wt. percent carbon formation.

The heavy hydrocarbon charge stock is contacted with hydrogen in the presence of the modified coke promoter in general at a temperature of from about 550 F. to about 900 F. preferably from about 725 F. to about 850 F.; pressures of from about 1,000 to about 6,000 p.s.i.g. preferably from about 2,000 to about 5,000 p.s.i.g.; liquid hourly space velocities of from about 0.1 to about 10 preferably from about 0.5 to about 2.5 volumes of feed per volume of contactor void space per hour; and hydrogen rates of from about 500 to about 20,000 preferably from about 2,500 to about 10,000 standard cubic feet (s.c.f.) per barrel of feed.

As stated above, the process of this invention utilizes a promoter selected from selectively oxidized coke and ammonia treated coke. It has been found that an oxidized coke wherein the yield of oxidized coke during the oxidation process of at least about 75 percent by weight based upon the original weight of coke is an effective promoter for the conversion of asphaltenes to lower boiling hydrocarbon. lt is preferred that the yield on a weight basis of oxidized coke be from 75-95 percent, more preferably, from -92 percent in order to provide maximum percent conversion of asphaltenes with substantially eliminated carbon deposits. By the use of the term "a coke yield of at least about 75 percent by weight" is meant that the yield of oxidized coke based solely upon the oxidation process be at least 75 percent by weight. Thus. reduction in yields below 75 percent by weight not attributable to losses through oxidation are not considered in determining a loss of yield. Thus, the loss of yield below 75 percent by weight such as by the formation of carbon monoxide and carbon dioxide during extensive oxidation of coke produces an oxidized coke which is not suitable as a promoter for the conversion of asphaltenes. In general the time and temperature during the oxidation step can be varied to produce a coke yield of at least about 75 percent by weight.

In carrying out the coke oxidation step an oxidant is utilized such as oxygen (including air and activated oxygen) ozone, organic peroxides, organic hydroperoxides and organic peracids, optionally in the presence of a metal catalyst, inorganic oxidants such as aqueous sulfuric acid and potassium dichromate solutions to produce an oxygen increase of up to about 4 wt. percent, more preferably up to about 2.5 wt. percent and preferably with uniform oxidation.

in general the concentration of oxidant is dependent upon the increase in oxygen content which is to be obtained during the oxidation step and the yield of oxidized coke obtained after the oxidation step. In general air rates (measured at standard conditions) of from about 20 to 400 preferably from about 30 to liters per hour per 100 grams of coke are used. In the case of inorganic oxidants. ozone, organic peroxides, organic hydroperoxides and organic peracids a concentration of oxidant generally within the range of from about 1.0 to about 5 moles of oxidant per mole of oxygen incorporated into the hydrocarbon material is utilized, more preferably from about 1.0 to about 2.5 moles of oxidant. It is preferred to use an excess of both air and other types of oxidant above that needed to incorporate the actual number of moles of oxygen (representing the oxygen increase) in the coke, preferably up to about 500 percent excess oxidant. The preferred oxidant which is utilized in carrying out the selective oxidation is oxygen (preferably air). When a catalyst is employed, it is preferred to use a catalyst concentration varying from about 0.0001 to about wt. percent based upon the weight of the coke and still more preferably from about 0.10 to about 10 wt. percent, the catalyst being used at a concentration which is sufficient to promote the effectiveness of the oxidant. In general the oxidant contacts the coke preferably with good agitation for a time generally within the range of from about minutes toabout 24 hours preferably from about one-half to about hours. The time that is utilized of necessity depends upon the'nature of the coke and the type of oxidant. In the case of a gas, the time can vary over a wide range depending upon the particular amount of gas such as air which contacts the coke. In general for the oxidation step utilizing air, an organic oxidant or inorganic oxidant, a temperature within the range of from about 70 F. to about 725 F., preferably within the range of from about 115 F. to about 700 F. is utilized. When ozone is utilized as the oxidant, a low temperature such as from 20 to about 125 F. is utilized. The quantity of oxidant utilized in the oxidation step can be obtained during the time utilized for the oxidation step. The coke oxidation process in general is carried out at atmospheric pressure although pressures above atmospheric for example up to about 100 atmospheres can be utilized. In order to prepare the ammonia-treated coke, the conditions as to time, temperature, pressure, and ammonia concentration can be varied over a wide range, those parameters being used which produce inner action of ammonia with coke. In general, ammonia, herein defined to. include both gaseous and liquid ammonia or an ammonia yielding substance is contacted with coke at a temperature of from about 750 to about 2,500 F., preferably from about 1,000 to about 2,000 F pressures of from about atmospheric pressure to about 1,500 p.s.i.g., preferably from about atmospheric to about 100 p.s.i.g.; and ammonia concentrations in the treating gas of about 10 to 100 percent, preferably 50 to 100 percent; and a treating dosage of 0.2 to 4 moles of ammonia per-100 grams of coke, preferably 0.5 to 2 moles of ammonia per 100 grams of coke with a total treatment time of from 10 minutes to 6 hours in batch or flow system but preferably 60 minutes to 4 hours in a continuous system whereby the treating gas is passed preferably at a uniform rate over the coke. In addition, the ammonia-treated coke promoters in general contain increases in nitrogen (basis total coke) of from 1 to about 4 weight percent. In general it is preferred to use an excess of ammonia over that which is required to incorporate the moles of nitrogen representing the nitrogen increase as set forth above. Thus, in general it is preferred to use at least up to about 500 percent excess ammonia. Typical examples of ammonia yielding substances are diand monoammonia phosphate, ammonium bicarbonate, ammonium citrate, ammonium acetate, ammonium salts of monocarboxylic acids and ammonium carbonate. In addition, ammonia can be. used in the liquid state, the vapor state, or dissolved in a solvent. In general. it is preferred to use ammonia per se in the vapor state.

As stated above the modified coke promoter can be continuously reused in the process of this invention, and regenerated after the activity of the modified coke promoter diminishes. In general, the conditions used to regenerate the modified coke promoter are those conditions set forth above for the preparation of the selectively oxidized coke and the ammonia treated coke. In certain cases wherein the activity of the modified coke promoter has diminished to a value whereby activity still remains, the length of time as to contact for contact with air or ammonia can be reduced. However, in general the process conditions withinthe above range as set forth above are utilized in regenerating the modified coke promoter.

The organic oxidants include by way of example hydrocarbon peroxides, hydroperoxides and hydrocarbon peracids wherein the hydrocarbon radicals in general contain from about one to about 30 carbon atoms per linkage. With respect to the hydrocarbon peroxides and hydrocarbon hydroperoxides, it is particularly preferred that such hydrocarbon radical contain from four to 30 carbon atoms per peroxide linkage and more particularly from four to 16 carbon atoms per peroxide linkage. With respect to the hydrocarbon peracids the hydrocarbon radical which is attached to the carbonyl carbon in general contains from one to about 12 carbon atoms more preferably from about one to about eight carbon atoms. It is intended that the term organic peracid includes-by way of definition performic acid.

Typical examples of hydrocarbon radicals are alkyl such as methyl, ethyl, butyl, t-butyl, 3-methyl-l-pentyl, n-octyl and those aliphatic radicals which represent the hydrocarbon portion of a middle distillate or kerosene, cycloalkyl radicals such as cyclopentyl, alkylated cycloalkyl radicals such as monoand polymethylcyclopentyl radicals, aryl and cycloalkyl substituted alkyl radicals such as phenyl and alkylphenyl substituted alkyl radicals examples of which are benzyl, methylbenzyl, caprylbenzyl, phenylethyl, phenylpropyl, naphthyb methyl, naphthylethyl, aryl radicals such as phenyl, and naphthyl, alkaryl radicals such xylyl, alkylphenyl, and ethylphenyl.

Typical examples of oxidants are hydroxyheptyl peroxide, cylohexanoneperoxide, t-butyl peracetate, di't-butyl diperphthalate, t-butyl perbenzoate, methylethylketone peroxide, dicumyl peroxide, t-butyl hydroperoxide, di-t-butylperoxide, p-methane hydroperoxide, pinane hydroperoxide, 2,5-dimethylhexane=2,S-dihydroperoxide and cumene hydroperoxide, organic peracids, such as performic acid, peracetic acid, trichloroperacetic acid, perbenzoic acid and perphthalic acid.

Typical examples of catalysts for use in the oxidation of coke, particularly with air, are potassium sulfate promoted vanadium oxide on alumina, vanadium oxide plus molybdenum oxide or alumina promoted with magnesium oxide, aluminum vanadate, vanadium oxide such as when prepared by hydrolysis of butyl vanadate with water in the presence of a porous catalyst carrier, vanadium oxide, silver oxide and stannic oxide on pumice, tin vanada on asbestos.

in general coke is comprised of minute graphitelike crystals imbedded in an organic matric of highly condensed aromatic compounds such as anthracene, phenanthracene. chrysene. picene and crakene. The petroleum coke used as a starting material in the process of this invention may be produced by the delayed coking" process, a process for converting heavy residual fuel oil into gasoline, gas oil, and coke. Other petroleum coking processes may be used such as "fluid coking. 1n the delayed coking" process, reduced crude oil is charged into the base of a fractionating tower. Tower bottoms and a predetermined recycle stream are withdrawn and heated to a temperature of 900-950 F. By delayed residence in coke drum, the petroleum coke builds up at a temperature of 850-900 F. and a pressure of 10-100 p.s.i. The petroleum coke is then cooled with water and removed from the delayed coker by hydraulic jet. The coke particles are quite hard and abrasive, and may contain sufficient oils to make them tacky. Existing petroleum coke plants vary in size from small units producing tons per dayto large multiple tower plants producing and handling as much as 1,500 tons per day. Petroleum coke generally has the following composition by weight: moisture 0 to about 0.25 percent volatiles from about 4 to about 7 percent, fixed carbon from about 92 to about 96 percent, ash from about 0.2 to about 1.3 percent, and sulfur from about 1.0 to about 5 percent.

A wide variety of asphaltene containing heavy hydrocarbon fractions may be treated, or made suitable for further processing, through the utilization of the method encompassed by the present invention. Such heavy hydrocarbon fractions usually contain from about 0.50 to about wt. percent asphaltenes and include full boiling range crude oils, topped or crude oils, vacuum tower bottoms, and visbreaker bottoms product. The present method is particularly well adaptable to the treating of crude oils and topped or reduced crude oils containing large quantities of asphaltenic material, and is especially advantageous when applied to the treating of atmospheric or vacuum towers bottoms e.g. especially 550 F. or higher atmospheric reduced crude oils.

The present invention can be carried out in batch, continuous or semicontinuous operating cycles, and in one or more actual or theoretical stages, employing contacting and separation equipment such as has heretofore been employed in hydrocracking of petroleum stocks. In addition a multistage mode or operation that is a repeating of the process several times can be utilized in carrying out the process of this invention.

The process of this invention can be better appreciated by the following nonlimiting examples.

EXAMPLE I To a reactor tube (three-quarters inch inner diameter by 16 inches in length) equipped with a diffusion disc at the bottom of said reactor tube, gas addition means at the bottom of said tube, exit means at the top of said tube and heating means is charged 30.5 grams of a delayed coke from California Crudes (30-60 mesh) having the following properties:

Sulfur, wt. 1.33 Carbon, wt. 1: 95.8 Ash. wt. k 0.71 Hydrogen, wt. 1: 4.1 Nitrogen, wt. i 2.4 Nickel. wt. 0.03 Vanadium, wt. i: 0.08 Iron, wt. Xv 0.023

Dry air is fed through the bottom gas addition means at a rate of 13.5 liters per hour at a temperature of 650 F. The temperature of the coke is maintained at 650 F. for a period of 12 hours. The produce is reduced in temperature and an oxidized coke is recovered having a wt. percent sulfur of 1.08 at a yield of 94 weight percent.

EXAMPLE ll EXAMPLE 111 To the reactor tube as described in example I is added 30.5 grams of California coke, the properties of which are set forth in example 1. Air at a temperature of 700 F. is continuously added to the coke at a rate of 13.5 liters per hour over a period of 10 hours and a temperature of 700 F. is maintained in the reactor. The temperature is reduced to ambient temperature and oxidized coke (1.34 weight percent sulfur) is recovered at a yield of 68.8 weight percent.

EXAMPLE IV To the reactor tube as described in example I is added 30.5 grams of California coke, the properties of which are set forth in example 1. Air at a temperature of 700 F. is continuously added to the coke at a rate of 13.5 liters pr hour over a period of 12 hours and a temperature of 700 F. is maintained in the reactor. The temperature is reduced to ambient temperature and an oxidized coke (1.29 weight percent sulfur) is recovered in a yield of 53 weight percent.

EXAMPLE V To a 300 milliliter reaction flask equipped with heating means and liquid addition means is added delayed coke from California Crudes grams-100 mesh) the properties of which are set forth above. To the coke is added 100 milliliters of water and the temperature is increased to 100 F. To this mixture is added a solution obtained by mixing 200 grams of water with 300 grams of 96 percent sulfuric acid and 24 grams of potassium dichromate. This solution is added to the coke through the liquid addition means over a period of one-half hour during which the temperature gradually increases to 132 F. The mixture is stirred for a period of 1 hour and the temperature allowed to attain ambient temperature over a period of 24 hours. The oxidized coke is filtered and washed with water four times until free of sulfate ion. The modified coke is then contacted with 100 milliliters of hydrochloric acid (8 wt. percent), vacuum filtered and washed free of chloride ion. The oxidized coke is dried and has a weight percent sulfur of 1.46 and is recovered in a yield of 97 weight percent.

EXAMPLE Vl To a Vycor tube equipped with gas addition means is added 27 grams of a 30-60 mesh delayed coke from California crudes the properties of which are set forth in example 1. Ammonia is introduced into the coke at a rate of 3 liters per hour and a temperature of 1,500 F. is maintained for a period of 4 hours. The modified coke is reduced to ambient temperature in a flowing stream of nitrogen. On analysis it was found that the treated coke had 3.56 weight percent nitrogen and a percent sulfur of 0.93.

EXAMPLE V11 To a 1,290 milliliter pressure reactor equipped with gas addition means is added 460 grams of a California atmospheric reduced crude oil having the following properties:

Gravity APl 15.2 Wt. asphaltenes (in 850F.+ material) Carbon Residue, wt. 8.54 Sulfur, wt. 1.58 Total Nitrogen, wt. 31; 0.74 DPl flask dist., wt. '36

[BF-850 F. 38.1 Residue 850 F.+ 61.9

together with 46 grams of the solid polymer (50-100 microns) from example 1. The reactor is flushed with hydrogen and the temperature is increased to 750 F. under a hydrogen atmosphere. A total pressure of 4,000 p.s.i.g. is maintained at 750 F. for a period of 42 hours. After this time the temperature is reduced to ambient temperature. It is determined that the hydrogen consumption based on the pressure drop is 850 standard cubic foot per barrel of charge. The oil is recovered from the pressure reactor and filtered to recover the solid polymer catalyst. It is determined that there is no carbon deposit formation.

EXAMPLE V11] To a 1,290 milliliter pressure reactor equipped with gas addition means is added 460 grams of a California atmospheric reduced crude oil the properties of which are set forth in example Vll together with 46 grams of the solid polymer (50-100 microns) from example 11. The reactor is flushed with hydrogen and the temperature is increased to 750 F. under a hydrogen atmosphere. A total pressure of 4,000 p.s.i.g. is maintained at 750 F. for a period of42 hours. After this time the temperature is reduced to ambient temperature. lt is determined that the hydrogen consumption based on the pressure drop is 750 standard cubic foot per barrel of charge. The oil is recovered from the pressure reactor and filtered to recover the solid polymer catalyst. It'is determined that there is no carbon deposit formation.

EXAMPLE IX To a 1,290 milliliter pressure reactor equipped with gas addition means is added 500 grams of a California atmospheric reduced crude oil the properties of which are set forth in example VII together with 50 grams of the solid polymer (50 to 100 microns) from example 111. The reactor is flushed with hydrogen and the temperature is increased to 750 F. under a hydrogen atmosphere. A total pressure of 4,000 p.s.i.g. is maintained at 750 F. for a period of 42 hours. After this time the temperature is reduced to ambient temperature. It is determined that the hydrogen consumption based on the pressure drop is 945 standard cubic foot per barrel of charge. The oil is removed from the pressure reactor and filtered to recover the solid polymer catalyst. It is determined that there is carbon deposit formation.

EXAMPLE X To a 1,290 milliliter pressure reactor equipped with gas addition means is added 460 grams of a California atmospheric reduced crude oil the properties of which are set forth in example VII together with 46 grams of the solid polymer (SO- 100' microns) from exampleIV. The reactor is flushed with hydrogen and the temperature is increased to 750 F. under a hydrogen atmosphere. A total pressure of 4,000 p.s.i.g. is maintained at 750 F. for a period of 42 hours. After this time the temperature is reduced to ambient temperature. It is determined that the hydrogen consumption based on the pressure drop is 610 standard cubic foot per barrel of charge. The oil is removed from the pressure reactor and filtered to recover the solid polymer catalyst. It is determined that there is heavy carbon deposit formation.

EXAMPLE XI Example VII is repeated using 500 grams of California atmospheric reduced crude and 50 grams of a delayed coke from the coking of a midcontinent crude the properties of which are as follows:

Sulfur wt. 1.29

Ash wt. 1.27

Hydrogen wt. 1; 3.9 Nitrogen wt. l: 1.2 Surface'area meter gram 5.0

After a period of 46 hours at a temperature of 750 F. and a hydrogen pressure of 4,000 p.s.i.g. it is determined that a heavy carbon deposit is formed.

EXAMPLE XII Example VII is repeated using 50 grams of California atmospheric reduced crude and 50 of carbon black the propertiesof which are as follows:

. Fixed Carbon, wt. 95 Volatile Carbon, wt. 5 Surface are, m.'lg. I I Particle Diameter 25 millimicrons After a period of 42 hours at a temperature of 750 F. and a hydrogen pressure of 4,000 p.s.i.g. it is determined that heavy carbon deposits are formed.

EXAMPLE XIII To the reactor tube as described in example l is added 37 grams of the recovered oxidized coke from examples VII and VIII. Air at a temperature of 650 F. is continuously added to the coke at a rate of 13.5 liters per hour over a period of 6 hours and a temperature of 650 F. is maintained. The temperature is reduced to ambient temperature and an oxidized coke 1.31 weight percent sulfur) is recovered.

EXAMPLE XIV To a 1,290 milliliter pressure reactor equipped with gas addition means is added 460 grams of a Californiaatmospheric reduced crude oil the properties of which are set in example VII together with 46 grams of the solid polymer (50-100 microns) from example Xlll. The reactor is flushed with hydrogen and the temperature is increased to 750 F. under a hydrogen atmosphere. A total pressure of 4,000 p.s.i.g. is maintained at 750 F. for a period of 42 hours. After this time the temperature is reduced to ambient temperature. It is determined that the hydrogen consumption based on the pressure drop is 750 standard cubic foot per barrel of charge. The oil is removed from the pressure reactor and filtered to recover the solid polymer catalyst. It is determined that there is no coke deposit formation.

EXAMPLE XV To a 1,290 milliliter pressure reactor equipped with gas addition means is added 460 grams of a California atmospheric reduced crude oil the properties of which are set forth in example VII together with 46 grams of the solid polymer (50-100 microns) from example V. The reactor is flushed with hydrogen and the temperature is increased to 750 F. under a hydrogen atmosphere. A total pressure of 4,000 p.s.i.g. is maintained at 750 F. for a period of 42 hours. After this time the temperature is reduced to ambient temperature. It is determined that the hydrogen consumption based on the pressure drop is 880 standard cubic foot per barrel of charge. The oil is removed from the pressure reactor and filtered to recover the solid polymer catalyst. It is determined that there is no coke deposit formation.

EXAMPLE XVI To a 1,290 milliliter pressure reactor equipped with gas addition means is added 460 grams of a California atmospheric reduced crude oil the properties of which are set forth in example VII together with 46 grams of the solid polymer (50-100 microns) from example VI. The reactor is flushed with hydrogen and the temperature is increased to 750 F. under a hydrogen atmosphere. A total pressure of 4,000 p.s.i.g. is maintained at 750 F. for a period of 42 hours. After this time the temperature is reduced to ambient temperature. It is determined that the hydrogen consumption based on the pressure drop is450 standard cubic foot per barrel of charge. The oil is removed from the pressure reactor and filtered to recover the solid polymer catalyst. It is determined that there is no coke deposit formation.

EXAMPLE XVII Example VII is repeated except that the solid polymer is omitted from the process. After a period of 44 hours, a temperature of 750 F. and a hydrogen pressure of 4,000 p.s.i.g. it is determined that a carbon deposit is formed.

The test results on the oil product obtained from examples VII through XVII are set forth below in table I.

The autoclave appearance at the end of the run was obtained through visual inspection. The percent disappearance of asphaltenes was determined by a modified procedure for deasphalting and deresinizing a crude oil described in analytical addition, Industrial and Engineering'Chemistry, volume 13, 1941, page 314. This procedure for determining asphaltene concentration comprises heating a sample (5 grams) together with milliliters of mixed hexanes. The liquid is filtered into a Gouch crucible (asbestos lined) leaving behind that material which settled from the mixed hexane. The settled material is continually treated with warm mixed hexanes until 9 10 a filtrate substantially water white is obtained. The solids contacting an asphaltene cpmaining heavy hydrocarbon which remain are then filtered into the Gouch crucible which charge stock Wlth hydrogen p h of a p q is rewashed until the color is water white. The Gouch crucible amount of a Promoter consisting essentially a fh containing asphaltenes is than air dried in an oven at coke promoter selected from the group conslstlng of oxidized coke, ammonia treated coke and mixtures thereof for a time sufficient under hydrogen contact conditions of pressure and temperature to convert at least a portion of the asphaltenes to lower boiling hydrocarbons and recovering lower boiling hydrocarbons, said oxidized coke being prepared by the ox- The difference in weight between the Gouch crucible before and after the hexane extraction is determined. The weight percent disappearance of asphaltenes is obtained by dividing the difference between the weight of asphaltenes in the charge and product by the weight of asphaltenes present in the charge Stock times 100 idation of coke in a yield of between about 75 percent and 97 TABLE I Recovered product from Example VII VIII IX X XI XII XIV XV XVI XVI-I Autoclave appearance at end of run. (l) (l) (l) 2 Wt. percent disappearance of asphaltenes. 73 65 0 0 20. 4 4 +940 77 5 0 35 4 0 1 Clean. 3 Heavy carbon deposit. 2 Carbon deposit. 4 Represents a total increase.

The results in table I demonstrate the outstanding effectiveh y Weight hased'upoh the Original hh cokeness of the process of this invention for converting asphaltenes A Process 0f clam 1 wherelh the X|d1zed Coke 13 which are present in a hydrocarbon charge stock to lower boil- P p y the p e s which comprises oxidizing coke in the ing hydrocarbons. More particularly, the process of this inven- Presence of an oxldaht Selected from the group consisting of tion provides for such conversion of asphaltenes without the YS P an inofganit; OXidafll. 020m, F g n Peroxide formation to any substantial degree of carbon or coke organic hydmperoxlde and an organ: peracd and the deposits. Thus, the results obtained in examples Vll, VIII, l zg gzgzg i hzg y the process which XIV, XV and XVI demonstrate that the modified coke 3 g l j promoter produces asphaltene conversion while eliminating 'Aprocess ofclalmzwherem the ox'dahils carbon deposits. These results are in sharp contrast to the low A process of claim I wherein the yield of oxidized coke i conversion of asphaltenes and heavy carbon deposits, utilizing from about 30 I about 92 wt. percent. an untreated delayed coke and carbon black, examples XI and 5. A process of claim 3 wherein the yield of oxidized coke is XII, wherein a +108 wt. percent increase in asphaltenes ocfrom about 80 to about 92 wt. percent. cuffed together with carbon depositsof addhiohal 6. A process of claim 5 wherein the coke comprises from portance is the fact that the nonselectively oxidized coke such about 4 to about 7 wt percent fl m f about 92 to as the coke Pmduced y Pwcedufes Ofexamples and Iv about 96 wt. percent fixed carbon, from about 0.2 to about 1.3 when utilized in asphaltene hydrocohversioh Process wt. percent ash and from about 1 to about 5 wt. percentsulfur. produced carbon deposits and heavy carbon deposits respec- A process of claim 3 wherein the promoter is oxidized tively with 0 weight percent disappearance of asphaltenes. In coke additi n a hydroconversion Process in the absence of a 40 8. A process of claim 6 wherein the promoter is oxidized modified coke promoter produced carbon deposits. Thus, the coke process of this invention produces conversion of asphaltenes to lower boiling hydrocarbons while minimizing carbon and coke formation during the process.

While this invention has been described with respect to various specific examples and embodiments it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.

We claim: 1. An asphaltene hydroconversion process which comprises 9. A process ofclaim 2 wherein the ammonia treated coke is prepared by the process which comprises contacting coke with gaseous ammonia.

10. The process of claim 1 in which the coke promoter consists essentially of oxidized coke which has been prepared by the oxidation of coke in a yield between 75 percent and 95 percent by weight based on the original weight of the coke. 

2. A process of claim 1 wherein the oxidized coke is prepared by the process which comprises oxidizing coke in the presence of an oxidant selected from the group consisting of oxygen, an inorganic oxidant, ozone, an organic peroxide, an organic hydroperoxide and an organic peracid and the ammonia treated coke is prepared by the process which comprises contacting coke with ammonia.
 3. A process of claim 2 wherein the oxidant is air.
 4. A process of claim 1 wherein the yield of oxidized coke is from about 80 to about 92 wt. percent.
 5. A process of claim 3 wherein the yield of oxidized coke is from about 80 to about 92 wt. percent.
 6. A process of claim 5 wherein the coke comprises from about 4 to about 7 wt. percent volatiles, from about 92 to about 96 wt. percent fixed carbon, from about 0.2 to about 1.3 wt. percent ash and from about 1 to about 5 wt. percent sulfur.
 7. A process of claim 3 wherein the promotor is oxidized coke.
 8. A process of claim 6 wherein the promotor is oxidized coke.
 9. A process of claim 2 wherein the ammonia treated coke is prepared by the process which comprises contacting coke with gaseous ammonia.
 10. The process of claim 1 in which the coke promoter consists essentially of oxidized coke which has been prepared by the oxidation of coke in a yield between 75 percent and 95 percent by weight based on the original weight of the coke. 